예제 #1
0
파일: looker.c 프로젝트: waruqi/tbox
/* //////////////////////////////////////////////////////////////////////////////////////
 * implementation
 */
static tb_long_t tb_dns_looker_reqt(tb_dns_looker_t* looker)
{
    // check
    tb_check_return_val(!(looker->step & TB_DNS_LOOKER_STEP_REQT), 1);
    
    // format it first if the request is null
    if (!tb_static_buffer_size(&looker->rpkt))
    {
        // check size
        tb_assert_and_check_return_val(!looker->size, -1);

        // format query
        tb_static_stream_t  stream;
        tb_byte_t           rpkt[TB_DNS_RPKT_MAXN];
        tb_size_t           size = 0;
        tb_byte_t*          p = tb_null;
        tb_static_stream_init(&stream, rpkt, TB_DNS_RPKT_MAXN);

        // identification number
        tb_static_stream_writ_u16_be(&stream, TB_DNS_HEADER_MAGIC);

        /* 0x2104: 0 0000 001 0000 0000
         *
         * tb_uint16_t qr     :1;       // query/response flag
         * tb_uint16_t opcode :4;       // purpose of message
         * tb_uint16_t aa     :1;       // authoritive answer
         * tb_uint16_t tc     :1;       // truncated message
         * tb_uint16_t rd     :1;       // recursion desired

         * tb_uint16_t ra     :1;       // recursion available
         * tb_uint16_t z      :1;       // its z! reserved
         * tb_uint16_t ad     :1;       // authenticated data
         * tb_uint16_t cd     :1;       // checking disabled
         * tb_uint16_t rcode  :4;       // response code
         *
         * this is a query 
         * this is a standard query 
         * not authoritive answer 
         * not truncated 
         * recursion desired
         *
         * recursion not available! hey we dont have it (lol)
         *
         */
#if 1
        tb_static_stream_writ_u16_be(&stream, 0x0100);
#else
        tb_static_stream_writ_u1(&stream, 0);          // this is a query
        tb_static_stream_writ_ubits32(&stream, 0, 4);  // this is a standard query
        tb_static_stream_writ_u1(&stream, 0);          // not authoritive answer
        tb_static_stream_writ_u1(&stream, 0);          // not truncated
        tb_static_stream_writ_u1(&stream, 1);          // recursion desired

        tb_static_stream_writ_u1(&stream, 0);          // recursion not available! hey we dont have it (lol)
        tb_static_stream_writ_u1(&stream, 0);
        tb_static_stream_writ_u1(&stream, 0);
        tb_static_stream_writ_u1(&stream, 0);
        tb_static_stream_writ_ubits32(&stream, 0, 4);
#endif

        /* we have only one question
         *
         * tb_uint16_t question;        // number of question entries
         * tb_uint16_t answer;          // number of answer entries
         * tb_uint16_t authority;       // number of authority entries
         * tb_uint16_t resource;        // number of resource entries
         *
         */
        tb_static_stream_writ_u16_be(&stream, 1); 
        tb_static_stream_writ_u16_be(&stream, 0);
        tb_static_stream_writ_u16_be(&stream, 0);
        tb_static_stream_writ_u16_be(&stream, 0);

        // set questions, see as tb_dns_question_t
        // name + question1 + question2 + ...
        tb_static_stream_writ_u8(&stream, '.');
        p = (tb_byte_t*)tb_static_stream_writ_cstr(&stream, tb_static_string_cstr(&looker->name));

        // only one question now.
        tb_static_stream_writ_u16_be(&stream, 1);      // we are requesting the ipv4 address
        tb_static_stream_writ_u16_be(&stream, 1);      // it's internet (lol)

        // encode dns name
        if (!p || !tb_dns_encode_name((tb_char_t*)p - 1)) return -1;

        // size
        size = tb_static_stream_offset(&stream);
        tb_assert_and_check_return_val(size, -1);

        // copy
        tb_static_buffer_memncpy(&looker->rpkt, rpkt, size);
    }

    // data && size
    tb_byte_t const*    data = tb_static_buffer_data(&looker->rpkt);
    tb_size_t           size = tb_static_buffer_size(&looker->rpkt);

    // check
    tb_assert_and_check_return_val(data && size && looker->size < size, -1);

    // try get addr from the dns list
    tb_ipaddr_ref_t addr = tb_null;
    if (looker->maxn && looker->itor && looker->itor <= looker->maxn)
        addr = &looker->list[looker->itor - 1];

    // check
    tb_assert_and_check_return_val(addr && !tb_ipaddr_is_empty(addr), -1);

    // family have been changed? reinit socket
    if (tb_ipaddr_family(addr) != looker->family)
    {
        // exit the previous socket
        if (looker->sock) tb_socket_exit(looker->sock);

        // init a new socket for the family
        looker->sock = tb_socket_init(TB_SOCKET_TYPE_UDP, tb_ipaddr_family(addr));
        tb_assert_and_check_return_val(looker->sock, -1);

        // update the new family
        looker->family = (tb_uint8_t)tb_ipaddr_family(addr);
    }

    // need wait if no data
    looker->step &= ~TB_DNS_LOOKER_STEP_NEVT;

    // trace
    tb_trace_d("request: try %{ipaddr}", addr);

    // send request
    while (looker->size < size)
    {
        // writ data
        tb_long_t writ = tb_socket_usend(looker->sock, addr, data + looker->size, size - looker->size);
        tb_assert_and_check_return_val(writ >= 0, -1);

        // no data? 
        if (!writ)
        {
            // abort?
            tb_check_return_val(!looker->size && !looker->tryn, -1);

            // tryn++
            looker->tryn++;

            // continue
            return 0;
        }
        else looker->tryn = 0;

        // update size
        looker->size += writ;
    }

    // finish it
    looker->step |= TB_DNS_LOOKER_STEP_REQT;
    looker->tryn = 0;

    // reset rpkt
    looker->size = 0;
    tb_static_buffer_clear(&looker->rpkt);

    // ok
    tb_trace_d("request: ok");
    return 1;
}
예제 #2
0
파일: dns.c 프로젝트: AlexShiLucky/tbox
/* //////////////////////////////////////////////////////////////////////////////////////
 * private implementation
 */
static tb_size_t tb_aicp_dns_reqt_init(tb_aicp_dns_impl_t* impl)
{
    // check
    tb_assert_and_check_return_val(impl, 0);

    // init query data
    tb_static_stream_t stream;
    tb_static_stream_init(&stream, impl->data, TB_DNS_RPKT_MAXN);

    // identification number
    tb_static_stream_writ_u16_be(&stream, TB_DNS_HEADER_MAGIC);

    /* 0x2104: 0 0000 001 0000 0000
     *
     * tb_uint16_t qr     :1;       // query/response flag
     * tb_uint16_t opcode :4;       // purpose of message
     * tb_uint16_t aa     :1;       // authoritive answer
     * tb_uint16_t tc     :1;       // truncated message
     * tb_uint16_t rd     :1;       // recursion desired

     * tb_uint16_t ra     :1;       // recursion available
     * tb_uint16_t z      :1;       // its z! reserved
     * tb_uint16_t ad     :1;       // authenticated data
     * tb_uint16_t cd     :1;       // checking disabled
     * tb_uint16_t rcode  :4;       // response code
     *
     * this is a query 
     * this is a standard query 
     * not authoritive answer 
     * not truncated 
     * recursion desired
     *
     * recursion not available! hey we dont have it (lol)
     *
     */
#if 1
    tb_static_stream_writ_u16_be(&stream, 0x0100);
#else
    tb_static_stream_writ_u1(&stream, 0);          // this is a query
    tb_static_stream_writ_ubits32(&stream, 0, 4);  // this is a standard query
    tb_static_stream_writ_u1(&stream, 0);          // not authoritive answer
    tb_static_stream_writ_u1(&stream, 0);          // not truncated
    tb_static_stream_writ_u1(&stream, 1);          // recursion desired

    tb_static_stream_writ_u1(&stream, 0);          // recursion not available! hey we dont have it (lol)
    tb_static_stream_writ_u1(&stream, 0);
    tb_static_stream_writ_u1(&stream, 0);
    tb_static_stream_writ_u1(&stream, 0);
    tb_static_stream_writ_ubits32(&stream, 0, 4);
#endif

    /* we have only one question
     *
     * tb_uint16_t question;        // number of question entries
     * tb_uint16_t answer;          // number of answer entries
     * tb_uint16_t authority;       // number of authority entries
     * tb_uint16_t resource;        // number of resource entries
     *
     */
    tb_static_stream_writ_u16_be(&stream, 1); 
    tb_static_stream_writ_u16_be(&stream, 0);
    tb_static_stream_writ_u16_be(&stream, 0);
    tb_static_stream_writ_u16_be(&stream, 0);

    // set questions, see as tb_dns_question_t
    // name + question1 + question2 + ...
    tb_static_stream_writ_u8(&stream, '.');
    tb_char_t* p = tb_static_stream_writ_cstr(&stream, impl->host);

    // only one question now.
    tb_static_stream_writ_u16_be(&stream, 1);      // we are requesting the ipv4 dnsess
    tb_static_stream_writ_u16_be(&stream, 1);      // it's internet (lol)

    // encode impl name
    if (!p || !tb_dns_encode_name(p - 1)) return 0;

    // ok?
    return tb_static_stream_offset(&stream);
}